Systems and Methods for Waveform Selection and Adaptation

ABSTRACT

Systems, methods, and apparatuses for providing waveform adaptation are provided. In an example, a method is provided for identifying a plurality of candidate waveforms, and selecting one of the candidate waveforms for data transmission. The candidate waveforms may be identified in accordance with one or more criteria, such as a transmission capability of the transmitting device, a reception capability of the receiving device, a desired Peak-to-Average-Power-Ratio (PAPR) characteristic, adjacent channel interference (ACI) rejection requirements, spectrum localization requirements, and other criteria. The waveform selected for data transmission may be selected in accordance with one or more waveform selection criteria, such as traffic characteristic, application types, etc.

TECHNICAL FIELD

The present invention relates generally to wireless communications, and,in particular embodiments, to techniques for selecting waveforms forcarrying wireless signals.

BACKGROUND

In modern wireless networks, a single waveform type is generally usedfor uplink communications, as well as downlink communications. Forinstance, fourth generation (4G) long term evolution (LTE) networksutilize an orthogonal frequency division multiple access (OFDMA)waveform for downlink communications and a single-carrier frequencydivision multiple access (SC-FMDA) waveform for uplink communications.Conversely, 4G Evolved High-Speed Downlink Packet Access (HSDPA+)networks utilize a code division multiple access (CDMA) waveform forboth uplink and downlink communications. Because each waveform has itsown advantages/disadvantages, no single waveform is optimal for allapplications. As such, the performance of conventional wireless networksis limited by virtue of using a single waveform.

SUMMARY OF THE INVENTION

Technical advantages are generally achieved by preferred embodiments ofthe present invention which describe systems and methods for waveformselection and adaptation.

In accordance with an embodiment, method of waveform adaptation isprovided. In this example, the method includes establishing a wirelesslink extending between a transmitting device and a receiving device,identifying a plurality of candidate waveforms for transporting trafficover the wireless link, selecting one of the plurality of candidatewaveforms in accordance with a waveform selection criteria, andcommunicating the traffic over the wireless link using the selectedcandidate waveform. Apparatuses for transmitting and receiving thetraffic in accordance with this method are also provided.

In accordance with another embodiment, another method of waveformadaptation is provided. In this example, the method includes receiving agrant request from a transmit point. The grant request requestsresources for communicating traffic in a channel of a wireless network.The method further includes establishing a wireless link in the channel,identifying a plurality of candidate waveforms in accordance with acapability of the transmit point, selecting one of the plurality ofcandidate waveforms in accordance with a traffic characteristic of thetraffic, sending a grant response that identifies the selected candidatewaveform, and receiving a transmission carried by the selected waveformfrom the transmit point. The transmission includes the traffic. Anapparatus for performing this method is also provided.

In accordance with yet another embodiment, another method of waveformadaptation is provided. The method includes receiving a first datatransmission in accordance with a first waveform type via a channel, andreceiving a second data transmission in accordance with a secondwaveform type via the channel. The second waveform type is differentthan the first waveform type, and first data transmission is receivedover different time-frequency resources of the channel than the firstdata transmission. Both the first data transmission and the second datatransmission comprise at least some data that is not classified assignaling or control information. An apparatus for performing thismethod is also provided.

In accordance with yet another embodiment, another method of waveformadaptation is provided. In this example, the method includestransmitting a first data transmission using a first waveform type in achannel, and transmitting a second data transmission using a secondwaveform type in the channel. The second waveform type is different thanthe first waveform type, and the second data transmission is transmittedover different resources of the channel than the first datatransmission. The first data transmission and the second datatransmission comprise at least some data that is not classified assignaling or control information. An apparatus for performing thismethod is also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a diagram of a communications network;

FIG. 2 illustrates an embodiment of a method for performing waveformadaptation;

FIG. 3 illustrates another embodiment of a method for performingwaveform adaptation;

FIG. 4 illustrates a diagram of a component for performing multi-stagewaveform adaptation;

FIG. 5 illustrates another embodiment of a method for performingwaveform adaptation; and

FIG. 6 illustrates a diagram of an embodiment of a communicationsdevice.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the preferredembodiments and are not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the presently preferred embodiments arediscussed in detail below. It should be appreciated, however, that thepresent invention provides many applicable inventive concepts that canbe embodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative of specific ways to makeand use the invention, and do not limit the scope of the invention.

As discussed above, conventional wireless networks use a single,statically selected, waveform throughout the life of the network.However, no single waveform is ideal for all conditions/situations. Byway of example, OFDMA waveforms exhibit comparatively high schedulinggain by virtue of frequency selective scheduling (FSS), which allowsOFDMA waveforms to outperform interleaved frequency division multipleaccess (IFDMA) waveforms when wireless channel conditions are good. Bycomparison, IFDMA waveforms can exhibit comparatively less out-of-band(OOB) interference by virtue of their low Peak-to-Average-Power-Ratio(PAPR) characteristics, which allows IFDMA waveforms to be able tooutperform OFDMA waveforms when wireless channel conditions are poor.Other categories of waveforms also exhibit advantages and disadvantages.For instance, non-orthogonal waveforms provide higher throughput, whileorthogonal waveforms require less processing/computational capacity(making them less burdensome to transmit and receive). As a consequenceof using a single, statically-selected, waveform, conventional wirelessnetworks are unable to adjust to changes in network conditions (e.g.,transmission and reception condition, traffic load, latencyrequirements, etc.), thereby leading to inefficiencies and reducedperformance. Accordingly, a mechanism for waveform adaptation isdesired.

Aspects of this disclosure provide a mechanism for adapting betweenvarious waveforms in accordance with network conditions and/or trafficrequirements, as well as an architecture for supporting multiplewaveforms concurrently in a single downstream or upstream channel. In anembodiment, waveform adaptation includes identifying a plurality ofcandidate waveforms in accordance with a UE's and/or transmit point (TP)capability, and thereafter selecting one of the candidate waveforms fordata transmission in accordance with a traffic characteristic or anetwork condition. In embodiments, different waveforms may coexist in asingle upstream or downstream channel by scheduling, or otherwisereserving, different time-frequency resources (e.g., frequency bands,timeslots, etc.) for different waveforms.

FIG. 1 illustrates a network 100 for communicating data. The network 100comprises a transmit point (TP) 110 having a coverage area 112, aplurality of user equipments (UEs) 120, and a backhaul network 130. Asdiscussed herein, the term transmit point (TP) may refer to any deviceused to transmit a wireless signal to another device, including a UE, abase station, an enhanced base station (eNB), a femtocell, etc. Forinstance, TPs may be a UE in an uplink communication or adevice-to-device (D2D) communication. The TP 110 may be any componentcapable of providing wireless access to the UEs 120-125. The TP 110 mayprovide wireless access by, inter alia, establishing an uplinkconnection (dashed line) and/or a downlink connection (dotted line) withthe UEs 120-125. The UEs 120-125 may be any component or collection ofcomponents that allow a user to establish a wireless connection forpurposes of accessing a network, e.g., the backhaul network 130. Thebackhaul network 130 may be any component or collection of componentsthat allow data to be exchanged between the TP 110 and a remote end (notshown). In some embodiments, the network 100 may comprise various otherwireless devices, such as relays, femtocells, etc.

FIG. 2 illustrates an embodiment of a method 200 for performing waveformadaptation over a downlink connection. The method 200 begins at step210, where a downlink connection is established for carrying trafficfrom the TP to the UE. Next, the method 200 proceeds to step 220, wherea plurality of candidate waveforms are identified in accordance with areception and/or processing capability of the UE. In some embodiments,the processing capability of the UE corresponds to an ability (orinability) to perform complex computation techniques, as may be requiredto process, inter alia, non-orthogonal waveforms. In embodiments, thestep 220 may also consider the transmission and/or processingcapabilities of the TP. Next, the method 200 proceeds to step 230, whereone of the candidate waveforms is selected in accordance with a waveformselection criteria. In an embodiment, the waveform selection criteriamay include a traffic characteristic and/or an application type. In thesame or other embodiments the waveform selection criteria may include anadjacent channel interference (ACI) rejection requirement and/or aspectrum localization requirement. Adjacent-channel interference (ACI)is interference caused by extraneous power from a signal in an adjacentchannel. Depending on the application scenario, different level of ACIrejection may be needed. For example, to make use of some gaps betweentwo occupied spectrums, the transmitter which transmits over the gapshould not cause extra emission to the existing spectrum and thereforeshould better restrict the out-of-band emissions. Different waveformsmay have different spectrum location feature. Spectrum localization mayrefer to the propensity of a waveform to generate interference inneighboring frequency bands, and may be a consideration in applications(e.g., cognitive radio) that have require low inter-channelinterference. In some embodiments, the traffic characteristic relates toa latency, QoS, or reliability constraint associated with a traffic typeof the data to be transmitted. For example, if the traffic type requireslow-latency (e.g., mobile gaming), then a waveform offering grant-lessaccess (e.g., CDMA) may be selected. Alternatively, if the traffic typerequires high reliability or high-bandwidth (e.g., transactionaltraffic, video, etc.), then a waveform offering grant-based access(e.g., non-CDMA, etc.) may be selected. As discussed herein, waveformsoffering grant-less access do not require the transmit point tocommunicate/signal grant information to the receiving device prior totransmitting the data, while waveforms offering grant-based accessrequire the transmit point to communicate/signal grant information tothe receiving device prior to transmitting the data. For instance, acontention-based access channel (e.g., a random access channel) may begrant-less, while a TDMA channel may be grant-based. After selecting thewaveform, the method 200 proceeds to step 240, where selected waveformis used to transport traffic to the UE via the downlink connection.Although the method 200 can be implemented by any network component atany time, it may typically be performed by the TP upon receivingdownlink data (e.g., data destined for the UE) from the backhaul networkor another UE.

FIG. 3 illustrates an embodiment of a method 300 for performing waveformadaptation over an uplink connection. The method 300 begins at step 310,where an uplink connection is established for carrying traffic from theUE to the TP. Next, the method 300 proceeds to step 320, where aplurality of candidate waveforms are identified in accordance with atransmission and/or processing capability of the UE. In embodiments, thestep 320 may also consider the reception and/or processing capabilitiesof the TP. Next, the method 300 proceeds to step 330, where one of thecandidate waveforms is selected in accordance with a waveform selectioncriteria. In an embodiment, the waveform selection criteria may includea traffic characteristic and/or an application type. In the same orother embodiments the waveform selection criteria may include an ACIrejection requirement and/or a spectrum localization requirement.Although the method 300 can be implemented by any network component atany time, it may typically be performed either by the TP upon (e.g.,upon receiving an uplink grant request from the UE) or by the UE (e.g.,before sending an uplink grant request to the TP). In some embodiments,the UE may be preconfigured to send data of a certain type (e.g.,low-latency, low-load traffic, etc.) over a frequency sub-band reservedfor grant-less waveforms, thereby avoiding the overhead associated withuplink grant requests.

FIG. 4 illustrates a high-level diagram of a component 400 forperforming multi-stage waveform adaptation. The component 400 comprisesa static waveform adaptation engine 410 and a dynamic waveformadaptation 420. The static waveform adaptation engine 410 is configuredto perform a first stage of waveform adaptation to identify a pluralityof candidate waveforms. In an embodiment, the candidate waveforms may beidentified in accordance with a transmission or reception (TX/RX)capability of the UE as well as physical layer parameters (e.g., PAPR,etc.). The dynamic waveform selection engine 420 is configured toperform a second stage of waveform adaptation by selecting one of theplurality of identified candidate waveforms for data transmission. In anembodiment, the dynamic waveform selection engine may select thecandidate waveform in accordance with a traffic characteristic orapplication type. In some embodiments, the static waveform selection 410may execute the first stage of waveform adaption once (e.g., uponformation of the uplink/downlink connection between the TP and/or UE),while the dynamic waveform selection engine 420 may be configured toperform the second stage of waveform adaption repeatedly (e.g., on aperiodic basis). In such embodiment, the waveform may be adapteddynamically in accordance with changing traffic characteristics and/ornetwork conditions. The dynamic waveform selection engine 420 may alsophysical layer parameters (e.g., PAPR, etc.), particularly duringsubsequent iterations so as to account for changes in wireless channelconditions.

FIG. 5 illustrates an embodiment of a method 500 for adaptive waveformselection. The method 500 begins at step 510, where physical layerparameters and/or the TP's Peak-to-Average Power Ratio (PAPR) toleranceare evaluated to determine whether a high or low PAPR waveform isdesired. Notably, PAPR tolerance may correspond to a pulse shapingcapability of the transmitting device, and may be related radiofrequency power amplifier performance, e.g., linearity, etc.Additionally, PAPR is a characteristic which significantly affects awaveform's propensity for generating interference in adjacent channels.Specifically, high PAPR waveforms (e.g., OFDMA, etc.) tend to exhibithigher out-of-band interference than low PAPR waveforms (e.g.,interleaved frequency division multiple access (IFDMA), etc.),particularly as transmit power is increased. Consequently, high PAPRwaveforms may produce higher bit error rates in adjacent frequencysub-bands for high transmit-power data transmission (e.g., when channelgain is low), thereby resulting in lower network throughput. Thetendency for high PAPR waveforms to produce or exhibit higherout-of-band interference is primarily attributable to power amplifiernon-linearity. Even so, high PAPR waveforms (e.g., OFDMA, etc.)generally provide better spectral efficiency than low PAPR waveforms(e.g., IFDMA, etc.).

The method 500 then proceeds to step 520, where the UE's TX/RXcapabilities are evaluated to determine whether an orthogonal ornon-orthogonal waveform is desired. Notably, the TP's TX/RX capabilitiesmay also be considered. However, from a practical standpoint, it maytypically be the TX/RX capabilities of the mobile device that limitwaveform selection. The TX/RX capabilities may correspond to the UE'sability to perform complex processing techniques, as may typically berequired of non-orthogonal waveforms. Notably, the UE's ability toperform complex processing techniques (e.g., equalization forinterference cancellation, MIMO detection, channel estimation to make upfor lack of cyclic prefix), etc.) may enable the use of waveforms thatrely on advanced modulation techniques. Thereafter, the method 500proceeds to step 530, where the application type is evaluated todetermine whether a grant-less or a grant-based waveform is desired. Agrant-less waveform (e.g., CDMA, etc.) may be selected if, for example,an application or traffic type has a low latency requirement, so as toavoid scheduling-related latency. Likewise, a grant-less waveform may beselected when there is a relatively small amount of data to transmit, soas to avoid the scheduling-related overhead. Alternatively, agrant-based waveform (e.g., non-CDMA, etc.) may be selected if, forexample, an application or traffic type has a high reliabilityrequirement, to reduce packet-error rates, or when there is a relativelylarge amount of data to transmit, to avoid having to re-transmit largeamounts of data.

In some embodiments, the steps 510-520 may be performed during a firststage of waveform selection (e.g., during static waveform selection),while the step 530 may be performed during a second stage of waveformselection (e.g., during dynamic waveform selection). Depending on theoutcome of the steps 510-530, one of a pool of possible waveforms willbe chosen for data transmission. In an embodiment, static waveformselection may be performed once (e.g., upon identifying the wirelesslink for transmission), while dynamic waveform selection may beperformed periodically or semi-periodically in accordance with a dynamicwaveform adaptation period. The pool of possible waveforms may includeany waveform that is capable of carrying a wireless transmission,including, but not limited to, IFDMA, OFDMA, CDMA, OQAM, and theirderivatives (e.g., IFDMA-CDMA, IFDMA-OQMA, OFDMA-CDMA, etc.). Eachwaveform in the pool of possible waveforms may have their own distinctadvantages and/or disadvantages. By way of example, OFDMA exhibits highPAPR and high scheduling gain through frequency selective scheduling(FSS), while IFDMA, by comparison, exhibits low PAPR and low frequencydiversity. By way of another example, pre-coded OFDM (e.g., singlecarrier (SC)-FDMA, etc.) exhibits mid-to-low PAPR and low frequencydiversity, while OFDM-CDMA exhibits high PAPR, scheduling-flexibility,and interference whitening for better link adaptation. Further still,various waveforms within the same class may exhibit differentcharacteristics. For instance, some non-orthogonal waveforms (e.g.,OFDM-OQAM) may exhibit lower OBB interference than other non-orthogonalwaveforms due to better frequency localization. As another example,OFDMA-QQAM may be pre-coded to achieve lower PAPR, or combined with CDMAto achieve contention based access.

When data originates from a single TP, multiple waveforms can co-existin a single channel (downlink, uplink, or otherwise) by assigningdifferent waveforms to carry different traffic streams (differentdata-transmissions). By way of example, a single TP may simultaneouslytransmit a video signal via a grant-based waveform, and transmit a shortmessage service (SMS) message via a grant-less waveform.

Multiple waveforms can also co-exist in a single channel (downlink,uplink, or otherwise) when the data originates from multiple TPs (or asingle TP) by scheduling different waveforms to different time-frequencyresources (e.g., frequency bands, time-slots/frames, etc.). Thisscheduling may be performed in a static, semi-static, or dynamicfashion. In one example, some frequency bands may be reserved for onecategory of waveforms (e.g., grant-less, orthogonal, etc.), while otherfrequency bands may be reserved for other categories of waveforms (e.g.,grant-based, non-orthogonal, etc.). For instance orthogonal andnon-orthogonal waveforms may be communicated in different frequencybands, with the frequency band scheduling/assignment being performedstatically, semi-statically, or dynamically. Waveform segregation canalso be achieved in the spatial domain, for instance, by using agrant-less waveform for beam targeting at the cell-edge and agrant-based waveform for beam targeting at the cell center. Low and highPAPR waveforms can coexist over any dimension.

FIG. 6 illustrates a block diagram of an embodiment of a communicationsdevice 600, which may be implemented as one or more devices (e.g., UEs,TPs, etc.) discussed above. The communications device 600 may include aprocessor 604, a memory 606, a cellular interface 610, a supplementalwireless interface 612, and a supplemental interface 614, which may (ormay not) be arranged as shown in FIG. 6. The processor 604 may be anycomponent capable of performing computations and/or other processingrelated tasks, and the memory 606 may be transient or non-transient andmay be any component capable of storing programming and/or instructionsfor the processor 604. The cellular interface 610 may be any componentor collection of components that allows the communications device 600 tocommunicate using a cellular signal, and may be used to receive and/ortransmit information over a cellular connection of a cellular network.The supplemental wireless interface 612 may be any component orcollection of components that allows the communications device 600 tocommunicate via a non-cellular wireless protocol, such as a Wi-Fi orBluetooth protocol, or a control protocol. The supplemental interface614 may be component or collection of components that allows thecommunications device 600 to communicate via a supplemental protocol,including wire-line protocols. In embodiments, the supplementalinterface 614 may allow the device 600 to communicate with a backhaulnetwork.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. Moreover, thescope of the present application is not intended to be limited to theparticular embodiments of the process, machine, manufacture, compositionof matter, means, methods and steps described in the specification. Asone of ordinary skill in the art will readily appreciate from thedisclosure of the present invention, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed, that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present invention.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps.

What is claimed is:
 1. A method of waveform adaptation, the methodcomprising: establishing a wireless link between a transmitting deviceand a receiving device; identifying a plurality of candidate waveformsfor transporting traffic over the wireless link; selecting one of theplurality of candidate waveforms in accordance with a waveform selectioncriteria; and communicating the traffic over the wireless link using theselected candidate waveform.
 2. The method of claim 1, whereinidentifying the plurality of candidate waveforms comprises identifyingcandidate waveforms, out of a plurality of possible waveforms, that areboth capable of being transmitted by the transmitting device and capableof being received by the receiving device.
 3. The method of claim 1,wherein identifying the plurality of candidate waveforms is performedstatically upon identifying the wireless link, and wherein selecting oneof the plurality of candidate waveforms in accordance with a waveformselection criteria is performed dynamically in accordance with a dynamicwaveform adaptation period.
 4. The method of claim 1, whereinidentifying the plurality of candidate waveforms comprises: determiningwhether the receiving device is capable of non-orthogonal signalprocessing; identifying at least some non-orthogonal waveforms ascandidate waveforms if the receiving device is capable of non-orthogonalsignal processing; and identifying only orthogonal waveforms ascandidate waveforms if the receiving device is incapable ofnon-orthogonal signal processing.
 5. The method of claim 1, whereinidentifying the plurality of candidate waveforms comprises: determininga Peak-to-Average-Power-Ratio (PAPR) tolerance of the transmittingdevice; and identifying candidate waveforms, out of a plurality ofpossible waveforms, having PAPR characteristics within the PAPRtolerance of the transmitting device, wherein waveforms having PAPRcharacteristics beyond the PAPR tolerance of the transmitting device areexcluded from the plurality of candidate waveforms.
 6. The method ofclaim 1, wherein the waveform selection criteria includes a trafficcharacteristic of the traffic or an application type of the traffic. 7.The method of claim 6, wherein selecting one of the plurality ofcandidate waveforms comprises: determining, in accordance with thetraffic characteristic or the application type, whether grant-basedaccess or grant-less access is better suited for transporting thetraffic; selecting one of the plurality of candidate waveforms thatoffers grant-less access in response to determining that grant-lessaccess is better suited for transporting the traffic; and selecting oneof the plurality of candidate waveforms that offers grant-based accessin response to determining that grant-based access is better suited fortransporting the traffic.
 8. The method of claim 7, wherein waveformsoffering grant-based access require that scheduling information becommunicated to the receiving device before communicating the trafficover the wireless link, and wherein waveforms offering grant-less accessdo not require that scheduling information be communicated to thereceiving device before communicating the traffic over the wirelesslink.
 9. The method of claim 7, wherein the traffic characteristiccomprises a quality of service requirement of the traffic.
 10. Themethod of claim 7, wherein the traffic characteristic comprises alatency constraint of the traffic.
 11. The method of claim 7, whereinthe traffic characteristic comprises a traffic load of the traffic. 12.The method of claim 1, wherein the waveform selection criteria includesa spectrum localization requirement.
 13. The method of claim 1, whereinthe waveform selection criteria includes an adjacent channelinterference rejection requirement.
 14. A transmit point in a wirelessnetwork, the transmit point comprising: a processor; and a computerreadable storage medium storing programming for execution by theprocessor, the programming including instructions to: establish awireless link in a channel of the wireless network for transportingtraffic to a receiving device; identify a plurality of candidatewaveforms in accordance with at least one of a capability of thereceiving device and a transmission capability of the transmit point;select one of the plurality of candidate waveforms in accordance with awaveform selection criteria; and perform a transmission in accordancewith the selected candidate waveform, the transmission carrying thetraffic to the receiving device via the wireless link.
 15. The transmitpoint of claim 14, wherein the instruction to identify the plurality ofcandidate waveforms includes instructions to: determine whether thereceiving device is capable of non-orthogonal signal processing;identify at least some non-orthogonal waveforms as candidate waveformsif the receiving device is capable of non-orthogonal signal processing;and identify only orthogonal waveforms as candidate waveforms if thereceiving device is incapable of non-orthogonal signal processing. 16.The transmit point of claim 14, wherein the instruction to identify theplurality of candidate waveforms includes instructions to: determine aPeak-to-Average-Power-Ratio (PAPR) tolerance of the transmit point; andidentify candidate waveforms, out of a plurality of possible waveforms,having PAPR characteristics within the PAPR tolerance of the transmitpoint, wherein waveforms having PAPR characteristics beyond the PAPRtolerance of the transmit point are excluded from the plurality ofcandidate waveforms.
 17. The transmit point of claim 14, wherein thewaveform selection criteria includes a traffic characteristic of thetraffic or an application type of the traffic.
 18. The transmit point ofclaim 17, wherein the instruction to select one of the plurality ofcandidate waveforms includes instructions to: determine, in accordancewith the traffic characteristic or application type, whether grant-basedaccess or grant-less access is better suited for transporting thetraffic; select one of the plurality of candidate waveforms that offersgrant-less access in response to determining that grant-less access isbetter suited for transporting the traffic; and select one of theplurality of candidate waveforms that offers grant-based access inresponse to determining that grant-based access is better suited fortransporting the traffic.
 19. The transmit point of claim 18, whereinwaveforms offering grant-based access require that schedulinginformation be communicated to the receiving device before communicatingthe traffic, and wherein waveforms offering grant-less access do notrequire that scheduling information be communicated to the receivingdevice before communicating the traffic.
 20. An apparatus comprising: aprocessor; and a computer readable storage medium storing programmingfor execution by the processor, the programming including instructionsto: receive, from a transmit point, a grant request for communicatingtraffic in a channel of a wireless network; establish a wireless link inthe channel; identify a plurality of candidate waveforms in accordancewith a capability of the transmit point; select one of the plurality ofcandidate waveforms in accordance with a traffic characteristic of thetraffic; send a grant response identifying the selected candidatewaveform; and receive, from the transmit point, a transmission carriedby the selected candidate waveform, the transmission comprising thetraffic.
 21. The apparatus of claim 20, wherein the instruction toidentify the plurality of candidate waveforms in accordance with thecapability of the transmit point includes instructions to: determine aPeak-to-Average-Power-Ratio (PAPR) tolerance of the transmit point; andidentify candidate waveforms, out of a plurality of possible waveforms,having PAPR characteristics within the PAPR tolerance of the transmitpoint, wherein waveforms having PAPR characteristics beyond the PAPRtolerance of the transmit point are excluded from the plurality ofcandidate waveforms.
 22. A wireless device comprising: a processor; anda computer readable storage medium storing programming for execution bythe processor, the programming including instructions to: determine, inaccordance with a waveform selection criteria of traffic, thatgrant-less access is better suited for transporting the traffic thangrant-based access, wherein the traffic comprises at least some datathat is not classified as signaling or control information; and transmitthe traffic in a resource of a wireless channel that is reserved forgrant-less waveforms, wherein the wireless channel comprises otherresources reserved for grant-based waveforms.
 23. A receiving devicecomprising: a processor; and a computer readable storage medium storingprogramming for execution by the processor, the programming includinginstructions to: receive a first plurality of data transmissions of afirst waveform type via a channel; and receive a second plurality ofdata transmissions of a second waveform type that is different than thefirst waveform type via a channel, wherein the second plurality of datatransmissions are received over different time-frequency resources ofthe channel than the first plurality of data transmissions, and whereinthe first plurality of data transmissions and the second plurality ofdata transmissions comprise at least some data that is not classified assignaling or control information.
 24. The receiving device of claim 23,wherein the programming further comprises instructions to: assign afirst frequency band to carry the first waveform before the firstplurality of data transmissions are received; and re-assign the firstfrequency band to carry the second waveform after the first plurality ofdata transmissions are received, wherein the first waveform and thesecond waveform are separated in the time domain or the spatial domain,wherein the first plurality of data transmissions are received over thefirst frequency band prior to the second plurality of data transmissionsare received over the first frequency band.
 25. The receiving device ofclaim 23, wherein the first waveform is orthogonal and the secondwaveform is non-orthogonal.
 26. The receiving device of claim 23,wherein the first waveform offers grant-less access and the secondwaveform offers grant-based access.
 27. A transmit point comprising: aprocessor; and a computer readable storage medium storing programmingfor execution by the processor, the programming including instructionsto: transmit a first data transmission using a first waveform type in achannel; and transmit a second data transmission using a second waveformtype that is different than the first waveform type in the channel,wherein the second data transmission is transmitted over differentresources of the channel than the first data transmission, and whereinthe first data transmission and the second data transmission comprise atleast some data that is not classified as signaling or controlinformation.
 28. The transmit point of claim 27, wherein the programmingfurther comprises instructions to: assign a first frequency band tocarry the first waveform before transmitting the first datatransmission; and re-assign the first frequency band to carry the secondwaveform after transmitting the first data transmission, wherein thefirst waveform and the second waveform are separated in the time domainor the spatial domain, and wherein the first data transmission istransmitted over the first frequency band prior to the data transmissionbeing transmitted over the first frequency band.
 29. The transmit pointof claim 27, wherein the first waveform is orthogonal and the secondwaveform is non-orthogonal.
 30. The transmit point of claim 27, whereinthe first waveform offers grant-less access and the second waveformoffers grant-based access.